Thinkpads Forum

The backlight on my T61P has been gracefully getting dimmer after five years and I think it is time to replace.

What are my options? Parts sources? Whole lid versus just a backlight?

A backlight is not an easy thing to replace. It's a very delicate operation.

yes its very hard .... i just change the lamp in my SXGA+ and it doesnt work again ... its not like CPU swap .... screen is not designed to be messing with ...

To give you an idea about CCFL replacing, see my write-up here: http://forum.thinkpads.com/viewtopic.php?f=31&t=88991

Soldering wires to the tube?! It sounds like Lenovo has made this into a cottage industry sending the pieces home with little old ladies to fab screens every night. And that the details will vary with the brand and type, just knowing the screen resolution won't necessarily tell me which parts I need?

I don't see how Lenovo is to be blamed for this one. LCD panels are intricate equipment, and when the CCFL backlight tube - an integral part of the panel - fails, you're supposed to replace the whole panel instead of repairing the panel by replacing the backlight tube, just like how you're supposed to replace the motherboard if one chip comes unsoldered. Of course, if you have the appropriate tools and skills, no one is stopping you from attempting the repair, and many have done so successfully, but it doesn't mean it's supposed to be done.

I don't say they're to blame, as such. But bulbs do burn out, and very few "bulbs" need to be installed by soldering against them. Someone figured out that contacts, or snap-in connectors, would double or triple the cost of the part, and then used a cheaper part figuring that in 4-5 years, most of them will be trashed anyway. Good economics, not so good engineering. But who values engineering these days anyway?

Same way that one of the hallmars of gen-you-whine IBM keyboards was that they used fdye-sublimated keycaps, not decals. Cheap keyboards (inlcuding all the Lenovo laptops) use decals on the keys, which often wear and wear off. The dye-sub keyboards simply never have that problem. One was designed to be used "forever" the other designed to be disposable and quickly replaced. AFAIK there are no more dye-sub keyboards, at any price, from any source. Economics trumps engineering.

Soldering of the CCFL wires was done for some very good reasons, not just economics.
1) the lifespan of an LCD and a CCFL is between 15'000 and 20'000 hours (5-8 years when 8 Hrs. on every day)
.... hardly necessary to replace it
2) there's almost no room for any connectors
3) when done properly, soldering makes much better contact than a connector
Considering there's up to ~1400 Volt going through those wires...

Five years, 1826 days, and I doubt I've averaged four hours per day but even then that would be less than 10,000 hours and the display has gotten DIM enough that it is hard to read when there's full sunlight coning in through the window. So, we can debate why and when, but yes, it may indeed need to be replaced, while the computer should not need to be replaced. The operating lifetime of ICs and other components ranges from 100-1000 years, literally 1000 years for ICs. There's no reason why a laptop couldn't be passed down, repurposed, kept in use for 10-20 years, just like a car or kitchen appliance.

No room? High voltage? Eh, engineers have gotten past all that. Soldering will ensure many things but hand soldering, as opposed to assembly-line production? Usually just means someone has a source of cheap hand labor. The Japanese used to send out buckets of parts for starter motors and alternators not so long ago--even in the 1980's--because cottage workers were cheap. The Chinese still do it today, you'll see little cases held together with a dozen screws instead of glue or rf welding, because screws work well for cottage workers.

And then there's Apple, who even seal up the battery, because allowing users to change their own battery, well, that would just be inconsiderable, wouldn't it? Good thing Lenovo allows us to swap out our own batteries! <VBG>


I'm betting that the bottom line on that lamp is simply economics, they probably shaved five bucks off the price of each display by doing it this way, and that gies them market share and volume. For most of the mass market? A dim display is a good thing, it means a good reason to buy a new computer!

First of all, let me get this straight. The CCFL backlight tube itself is soldered to two wires at its ends, and the wires then lead to a connector that plugs into the inverter. If you can find a complete tube+wire combination that has the correct length of wires, you could technically replace the tube without soldering. It's just that many online sellers only sell bare tubes. Now:

hellosailor wrote:But bulbs do burn out, and very few "bulbs" need to be installed by soldering against them. Someone figured out that contacts, or snap-in connectors, would double or triple the cost of the part, and then used a cheaper part figuring that in 4-5 years, most of them will be trashed anyway. Good economics, not so good engineering. But who values engineering these days anyway?

Very few bulbs are 1 millimeter in diameter and 300 millimeters in length. Very few bulbs are installed in such a clean environment that does not tolerate even a speckle of dust or minute amount of finger grease. Very few bulbs are carried around, bumped around, even dropped, both while off and while on.
The point is, a CCFL backlight tube is not your average bulb. It is a very specialized piece of equipment. To properly disassemble an LCD panel, the least you should have is a clean room; this is very, very, very much different from replacing the light bulb in your room lights which you can install with bare hands.

hellosailor wrote:So, we can debate why and when, but yes, it may indeed need to be replaced, while the computer should not need to be replaced. The operating lifetime of ICs and other components ranges from 100-1000 years, literally 1000 years for ICs. There's no reason why a laptop couldn't be passed down, repurposed, kept in use for 10-20 years, just like a car or kitchen appliance.

Where did you get this idea that laptops should last forever? Just because there are other things that last? Even cars do age, as do kitchen appliance. An old car probably have lots of parts replaced during its lifetime, no? The dimming of CCFL backlight is part of normal aging of a laptop.

hellosailor wrote:Soldering will ensure many things but hand soldering, as opposed to assembly-line production? Usually just means someone has a source of cheap hand labor.

First of all, how do you know CCFL backlight tubes are hand-soldered at the factory instead of machine-soldered? I have not seen anything related to that in this thread yet.
Second, what's wrong with cheap hand labor if they do a better job than machines? You seem to equate hand labor with low quality, but there are a lot of jobs that are simply impossible for machines to do at our current level of technology.

hellosailor wrote:I'm betting that the bottom line on that lamp is simply economics, they probably shaved five bucks off the price of each display by doing it this way, and that gies them market share and volume. For most of the mass market? A dim display is a good thing, it means a good reason to buy a new computer!

And I'm betting that soldering the ends of the CCFL tube is the only viable solution to that problem, and it has little to do with cost, and it doesn't matter anyways because anyone who replaces these things properly has access to a clean room, therefore they also have access to soldering irons if they wish. An end user or even the laptop's manufacturer is only supposed to replace the whole LCD panel, not parts within the panel.
Too bad I'm not an LCD engineer, and neither is you. But at least I have taken apart several LCD panels and can appreciate the intricate engineering that went into these things.

" Very few bulbs are installed in such a clean environment that does not tolerate even a speckle of dust or minute amount of finger grease."
Actually, all halogen bulbs are installed grease-free without finger contact. Buy a new one for a floor lamp, and the box will carry the same instructions not to touch it with bare fingers. Speckle of dust? No, they all withstand that.

"a CCFL backlight tube is not your average bulb. It is a very specialized piece of equipment."
Got one in my scanner, too. Which moves back and forth with every scan, and is exposed to cooling air and dust without incident.

"To properly disassemble an LCD panel, the least you should have is a clean room; "
Oh, it ain't a had drive. Especially the bulb. And while every warranty repair shop replaces screens, none of them have clean rooms. It just isn't necessary unless you are taking the screens themselves apart.

"Where did you get this idea that laptops should last forever?"
I didn't say forever, I said 10-20 years, like many other consumer products. A laptop is mainly a solid state piece of electronics, with a tested and confirmed life expectancy in excess of 100 years. That's what the USAF and Motorola say is normal for "discrete" electronic components in a properly engineered device, not my opinion. That's also the typical lifetime of a TV or stereo, similar devices, and many larger household appliances. Sure, they age, some need service, some consume parts, I'd bet your car would be cheaper if they just tack-welded the wheels on instead of using all those nasty bolts.<G>

"The dimming of CCFL backlight is part of normal aging of a laptop." RIGHT! Which is why I say normal aging and normal replacement of parts should be considered and made simple in manufacturing. But these days, the final stage of manufacturing is often an engineer whose job is to say "We can get rid of this, this, and that, it will still work well enough and cost less to sell."

"Please show me a connector that is..." You've mistaken me for a catalogue house. Why not have the wire leads extend out of the bulb, and then simply take the wires to simple pin plugs? Or wire wrap them to posts? Yes, wire wrap, which is also about 100x more reliable than solder on PC boards and other applications. Not my opinion--that's the USAF speaking gain.

"First of all, how do you know CCFL backlight tubes are hand-soldered at the factory instead of machine-soldered?" I didn't say they were. I said hand-soldered by COTTAGE WORKERS AT HOME. The point is not WHERE the job is done, but if you are soldering loops of wire to a glass tube, peasants with soldering guns is cheaper than setting up robotic arms.

"Second, what's wrong with cheap hand labor if "
You're reading things I haven't written, or even implied. There's nothing wrong with cheap hand labor, or exploiting cottage workers. It USUALLY is exploitation, because they get no benefits, no assurance of hours, no nothing. Like the piecework that the US garment industry used to do, and like most sweatshops still running today. Actually, it beats sweatshops, because the workers provide their own workplace and that saves on the rent as well. I don't say Lenovo does this, or does it any differently from the US and Japan and the rest of the world. I just suggest this would be an ideal way to job out a task best done cheaply by hand, off the assembly line.


" But at least I have taken apart several LCD panels and can appreciate the intricate engineering that went into these things."
Engineering? I couldn't care less if you were Mr. Eiffel and engineered the Eiffel Tower. Apparently you just don't get the point: Engineering has nothing to do with mass-market products. Mass-market products are all about COST and the engineers be [censored]. IBM dumped their computer business because they couldn't figure out how to make money at it. The Chinese bought it, because among other things they are pretty good about knocking costs down to the bone.
Our Lenovos are not the product of the world's finest engineers, they are the product of competent engineers working for some of the sharpest cost-cutters on the planet.

Does your wrist-rest squeek? Flex a little? Had any cracks on the lid back? There's proof of cost-concious manufacturing all over these laptops, just as there is on most computers. IBM lost money on them. Lenovo makes gobs of money on them. Ask yourself, what changed? The new owners have a sharp eye for costs, that's all.

C'mon guys, this is not a pissing contest...

Alright, I'll stick to facts only.

hellosailor wrote: Oh, it ain't a had drive. Especially the bulb. And while every warranty repair shop replaces screens, none of them have clean rooms. It just isn't necessary unless you are taking the screens themselves apart.

And that's exactly what changing a CCFL backlight involves: taking the screen themselves apart. As I said, the CCFL backlight tube is an integral part of the LCD panel.

hellosailor wrote:Why not have the wire leads extend out of the bulb, and then simply take the wires to simple pin plugs?

That's exactly what they do with every CCFL-backlit LCD panels out there, too. Only when you're replacing it with a generic tube - not a pre-assembled tube with wires already soldered on - do you need to solder them yourself.

hellosailor wrote:I didn't say they were. I said hand-soldered by COTTAGE WORKERS AT HOME.

How do you know that, then? RBS linked to a post detailing his personal experience of changing a CCFL. Nowhere in this or that post do I see descriptions of workers soldering CCFL tubes at home en masse.

RealBlackStuff wrote:To give you an idea about CCFL replacing, see my write-up here: http://forum.thinkpads.com/viewtopic.php?f=31&t=88991

RBS i didnt read your manual before but i did the same job i even buy this new isolation to cover the solder ... but the screen didnt start after surgery ... i am pretty shure i did it at least good ... hmmm maybe i will disassembled it again but not now ... my mental health is more important than an IPS screen